Brands have sought to partner with influential bloggers for nearly as long as there have been blogs, with ads, sponsored posts, and more. Lately, however, a new relationship between brands and popular social media practioners is emerging: It’s not a traditional endorsement deal, and yet an “independent” endorsement for the brand is all but guaranteed.

So how exactly does that work?

Well, for the companies involved, there is a simple two-step approach to establishing such relationships: 1) Locate people who love your brand and hold influence in the social media world; and 2) give these people even more reason to love your brand, so that they’ll use their influence to somehow help promote that brand.

Chipotle is following such a strategy by giving free burritos for life to pro athletes. Free burrito cards aren’t being handed out willy-nilly to every well-known athlete, of course. Instead, the criterion is pretty obvious: The freebies are given to athletes who have already stated publicly (via Twitter, most likely) that they love Chipotle.

[CLARIFICATION: A firm representing Chipotle reached out and clarified that these cards don’t guarantee free burritos for life. Instead, cardholders get one free burrito per day for one year, with the opportunity to renew when the 12-month period is over.]

The fast-casual chain is banking on the strong likelihood that if these athletes are munching on its burritos for free regularly, they’ll plug the brand occasionally. The athletes aren’t official spokespeople and aren’t featured in company ads. But in essence, they are endorsing Chipotle, and they’re being “paid” for their endorsement in the form of free burritos.

Popular bloggers, on the other hand, often agree to relationships with brands that might include official sponsorships, invitations to focus groups on products in the works, or special perks such as freebies or sneak peeks at merchandise before it’s in stores. In 2009, the FTC released guidelines that require full disclosure of “material connections”—sponsorships, free products and perks, and any money changing hands whatsoever—between advertisers and endorsers, bloggers included. For example, Walmart stipulates that all bloggers participating in its Walmart Moms program must “disclose their relationship with Walmart as well as any compensation received, including travel opportunities, expenses or products.”

What the rules can’t require is for bloggers to be 100% honest and forthright in their reviews and social media plugs, leading some to question the credibility of any “independent” voice partnering with a corporate brand.

A recent Minneapolis Star-Tribune story raised some concern about Target’s “Inner Circle,” a group of 16 bloggers that the retailer recruited last year and flew to New York City and Minneapolis to meet with company executives, try out new products, and generally have a fun time. A Target spokesperson explained to the Star-Tribune that these bloggers are “absolutely free to write what they see,” and that, “we are looking for authenticity.”

And yet, because Target handpicked the group at least partially because they’re fans of the retailer, the impression is that it’ll be extremely rare for a member of the Inner Circle to say anything remotely negative about Target. When Alyson Seligman, author of The Average Girl’s Guide blog, found out she was accepted in Target’s Inner Circle, she shared the “amazing news” with her readers: “I literally feel my heart bursting out of my chest with excitement with this one.” In a post in early December, soon after the Inner Circle’s trip to New York City, Seligman raved about Target’s Neiman Marcus collection, which wound up being almost universally bashed as an overpriced flop by shoppers and analysts. “I have a borderline obsessive love for Target,” she told the Star-Tribune.

Upon finding out she was officially chosen for the Inner Circle, designer Jennifer Pebbles gushed on her Studio Pebbles blog that she was being flown to New York City, and reflected on how long she’s been smitten by Target:

I have had a love affair with all things Target for as long as I can remember, back to the days when Micheal Graves made those hot looking kitchen appliances and told us that design was for everyone, everyday, at any price.

In a RetailWire post about the emergence of the Inner Circle, several commenters—who list their full names and statuses as pros in retail and consulting—noted that the initiative could backfire if and when a blogger’s objectivity is called into question. As one comment put it:

Does anyone believe that someone who starts out as an avid Target fan and then gets the royal treatment from Target will be unbiased in their blogs? Any credibility that they had should have gone away when Target recruited them to its inner circle.

Amy Mascott, an Inner Circle member who blogs about parenting at TeachMama.com, told me via e-mail that she has always liked Target, and that she thought her readers would enjoy a behind-the-scenes look at what the retailer does—but that Inner Circle bloggers are under no obligation whatsoever to promote Target or its products. “Obviously they’d hope that we would share the experience, and many of us wanted to, but Target never put pressure on us to do so,” she said. “One thing I appreciate about the program is the complete openness and its stress-free nature.”

As for concerns about credibility in such relationships, Mascott responded, “As long as any blogger is being open and honest about his or her relationship with brands and is abiding by the FTC guidelines, then I don’t see a problem.”

Still, she acknowledged that anytime a blogger—or company, for that matter—enters into a business relationship with a brand, there are risks. Mascott’s blog has had several sponsorships, including Target, toymaker Melissa & Doug, and clothing maker Land’s End, and while considering any possible partnership, she asks herself things like: “Will readers stick around and continue as loyal subscribers? How many brand relationships is too many? How many sponsored posts vs. un-sponsored posts?”

Melissa Garcia, who blogs at ConsumerQueen.com and has been a member of the Walmart Moms community, said via e-mail that over the years she has turned down many brand partnership opportunities because they weren’t a good fit for her, and they could damage her relationship with readers. “Most of the bloggers I know (myself included), have spent many years growing our blogs and working hard to gain the trust of our readers,” she explained. “I would never want to jeopardize the relationships I have worked so hard to build for a brand that I didn’t believe in or for products I didn’t like.”

If and when readers are turned off by too many sponsorships or get the impression a blogger is little more than a shill, the blogger is likely to hear about it, in the form of nasty comments or a falloff in page views, or perhaps the loss of another sponsorship. This is all part of the equation for the blogging world today. “The great thing about reading blogs is that there’s never any pressure to do anything,” explained Mascott. “If someone likes the content, she subscribes or visits. If not, she doesn’t. Done. On to the next one!”